The following disclosure relates to droplet ejection devices, such as inkjet printers.
Inkjet printers are one type of apparatus employing droplet ejection devices. In one type of inkjet printer, ink drops are delivered from a plurality of linear inkjet print head devices oriented perpendicular to the direction of travel of the substrate being printed. Each print head device includes a plurality of droplet ejection devices formed in a monolithic body that defines a plurality of pumping chambers (one for each individual droplet ejection device) in an upper surface. A flat piezoelectric actuator covers each pumping chamber. Each individual droplet ejection device is activated by applying a voltage pulse to the piezoelectric actuator, which distorts the shape of the piezoelectric actuator and discharges a droplet at the desired time in synchronism with the movement of the substrate past the print head device.
Each individual droplet ejection device is independently addressable and can be activated on demand in proper timing with the other droplet ejection devices to generate an image. Printing occurs in print cycles. In a print cycle, a fire pulse is applied to all of the droplet ejection devices at the same time, and enabling signals are sent to only to those droplet ejection devices that are to jet ink in that print cycle.